Oil and/or fuel in lower intake manifold....

[ninz30]

After removing the upper half of the intake manifold, I noticed oil in all four lower intake channels. Number three (the one pictured) has an oil coolant mix. I did perform a wet and dry compression test and all cylinders had adequate psi. I measured and added 2cc of 5w30 to each cylinder for the wet test. Any advice would be much appreciated! thank you in advance and happy wrenching.

[timsrv]

Hard to say for sure. How many miles are on it? If your piston rings are allowing lots of blow-by, this can overwhelm your pcv system with oil vapor. How much did your compression improve when you added oil to the cylinders? Coolant shouldn't be there......unless maybe from a cracked head or a blown head gasket, but if that were the case you would have likely experienced other symptoms (like steam out the exhaust, loss of coolant, coolant in your oil, oil in your coolant, etc). You would have had to remove the coolant bypass hoses from your throttle body to remove the upper half, perhaps some dripped down there when you weren't looking???

[ninz30]

I think it did drip when I removed the upper intake. I'm thinking its the pcv valve. The compression test didn't improve much with the oil. An avg of 7psi. It has 190k. I drained the oil and it has no coolant in it also.

[Filippo]

I finally managed to get the intake manifold off and found that one of the ports (the left one) has standing fuel in it. Why would this happen? and what would I have to do to repair the problem. I dont imagine its how it should be since only one has fuel.2509

[originalkwyjibo]

Sounds like that injector is leaking.

[Filippo]

I was hoping that is all it is. I just didnt want to reassemble everything and have left a major issue unfixed. I plan to replace the injectors anyway.

[Filippo]

Well, replaced fuel pump, fuel sender, filter, pulsation damper, fuel pressure regulator, got refurbed injectors and cold start tested and cleaned, cleaned out the tank and high pressure lines. Still no crank. Still low pressure in the fuel rail. Gonna check the pressure in the line right after the pump. If its low there i guess i need to see whats wrong in the tank. Any ideas as to why else fuel pressure might be low? There is a small crimp just before the damper. Ill post a pic later of it. Wouldnt think it would be enough to cause 15 psi pressure in the rail.

[Jlhollowx13]

Ok so I just got new injectors and am in the process of installing them. When I split the intake manifold there seems to be oil in it, it also seemed to seep onto the gasket mating surface, so not a huge amount but enough to run like that. It's also very dirty in my intake and throttle body, like black and oily, I just did my head gasket and cleaned everything up so I feel like it shouldnt be this dirty. I've also seemed to be going through oil a bit, what can be causing this? I'd like to figure it out in case it's something I can fix while I'm in here. Thanks for any help!

[Jlhollowx13]

I read up on some posts and Tim said you can look and see if the residue is coming from the cold start injector or the pcv/breather side. I'm going to check tomorrow and see if there is any sign from either as I do have cold start issues that could be related to a leaking cold start injector. Can cold start injectors be rebuilt?

Anymore ideas are welcome!

[timsrv]

Here's a quote from another thread regarding this:


If the gunk inside your manifold has a trail that leads to the PCV and valve cover vent ports, then it's due to crank-case ventilation and can be normal. Intake manifolds eventually get fouled up inside due to the PCV (Positive Crankcase Ventilation) and the valve cover vent hose. These 2 larger intake ports suck the oily vapor out of the top your valve cover and recycle it back into the combustion areas. This is good because it helps prevent the formation of sludge and condensation inside the engine. It also keeps the interior of the engine at a slight negative pressure which helps inhibit external oil leaks (reduces the outward pressures on the gaskets and seals). The down side to oily vapor moving through your intake manifold is a gradual build up of oily residue inside. This build-up is very gradual but steady. Another negative aspect to crank case ventilation is over time this build-up problem becomes accelerated (due to normal engine wear). As the piston rings wear they slowly allow more and more combustion pressure/gasses to escape down and around the piston and into the crank case. The combined combustion leaks from multiple cylinders can eventually match or overcome the CFM (Cubic Feet per Minute) of vapor these vent ports can move.........and that creates a positive pressure inside the engine.

Now instead of these vent ports sucking in small amounts of vapor, they become overwhelmed by positive pressure force feeding combustion gasses into them (for a 2nd trip through the engine along with the additional vaporized oil that was picked up along the way).

One of the things you can do to check for blow-by is remove the PCV valve from the valve cover while the engine is running (leave the valve hooked up to the vacuum hose). If you can see and feel vapor puffing out of the valve cover, then you have a blow-by issue. This can be a good indication that it's time for a rebuild or at least a new set of rings.

If the residue trail inside the manifold goes back to the cold start injector, then it's possible this injector has been leaking and the build up is a result of that. Tim

And here's a link to another thread of the same subject:

http://www.toyotavantech.com/forum/showthread.php?2103-Oil-in-lower-intake-manifold

[Jlhollowx13]

Thanks tim, that's actually the exact quote I was referring to from you haha. I looked and can't really tell, it all looks about even, but definitely a bit more wet near the pcv and breather ports. Being as the pcv is new I'm guessing it's just blowby that I can't control? Worn rings?

I do see some evidence of stuff coming out of the cold start injector, the carbon build up near there has a spray pattern outward from the injector but I'd expect that to be normal. The little hole the injector sits in and around it just have dry carbon deposits, not oily/wet like everywhere else.

Ill be reinstalling everything tomorrow so any ideas on other things to check while it's apart are much appreciated. I'll pull the pcv hose and check for suction/blowby when I get it all back together but that will indicate a worn engine.

[timsrv]

Is it possible that it's actually dirty gasoline that only looks like oil? Over the years it gets gunky/dirty in there, and if you have gas leaking from the cold start injector, it could dissolve and pick-up some of that on it's way to the lower manifold. In a well ventilated area like your manifold, the gas would evaporate quickly and might only leave a thick dirty residue behind. I've purchased a couple of these cold start injectors off eBay and had good luck with them. Here's a link to the auction:

http://www.ebay.com/itm/TOYOTA-VAN-WAGON-TOYOTA-VAN-COLD-START-VALVE-23260-79085-/360757622659?hash=item53fed47783:g:XckAAOxyAs9STye b

[Jlhollowx13]

Is it possible that it's actually dirty gasoline that only looks like oil? Over the years it gets gunky/dirty in there, and if you have gas leaking from the cold start injector, it could dissolve and pick-up some of that on it's way to the lower manifold. I've purchased a couple of these off eBay and had good luck with them. Here's a link to the auction:

http://www.ebay.com/itm/TOYOTA-VAN-WAGON-TOYOTA-VAN-COLD-START-VALVE-23260-79085-/360757622659?hash=item53fed47783:g:XckAAOxyAs9STye b

Thanks, that's much better than the $100+ price from toyota or rockauto. Can they be sent to Dr injector?

[timsrv]

I don't know. These are not a standard configuration injector, so I would wonder if he has the right adapter(s) to test. If you're sending other injectors it wouldn't hurt to send along for the ride. Injectors are their specialty, so you never know. Tim